Nano memory, light, energy, antenna and strand-based systems and methods

ABSTRACT

An apparatus includes a first array of transistor elements; a second array of carbon nano-elements formed above or below the first array of transistor elements; and a circuit coupled to the first array to access the carbon nano elements.

This application is a continuation of U.S. application Ser. No.11/369,103, which is a continuation of application Ser. No. 11/690,937,which in turn is a continuation in part (CIP) application claimingpriority to U.S. application Ser. No. 11/064,363, filed Feb. 23, 2005and entitled “Nano Electronic IC Packaging”, the content of which isincorporated by reference.

BACKGROUND

This invention relates in general to nano electronic devices.

Important characteristics for a memory cell in electronic device are lowcost, nonvolatility, high density, low power, and high speed.Conventional memory solutions include Read Only Memory (ROM),Programmable Read only Memory (PROM), Electrically Programmable Memory(EPROM), Electrically Erasable Programmable Read Only Memory (EEPROM),Dynamic Random Access Memory (DRAM) and Static Random Access Memory(SRAM).

ROM is relatively low cost but cannot be rewritten. PROM can beelectrically programmed but with only a single write cycle. EPROM hasread cycles that are fast relative to ROM and PROM read cycles, but hasrelatively long erase times and reliability only over a few iterativeread/write cycles. EEPROM (or “Flash”) is inexpensive, and has low powerconsumption but has long write cycles (ms) and low relative speed incomparison to DRAM or SRAM. Flash also has a finite number of read/writecycles leading to low long-term reliability. ROM, PROM, EPROM and EEPROMare all non-volatile, meaning that if power to the memory is interruptedthe memory will retain the information stored in the memory cells.

DRAM stores charge on transistor gates that act as capacitors but mustbe electrically refreshed every few milliseconds complicating systemdesign by requiring separate circuitry to “refresh” the memory contentsbefore the capacitors discharge. SRAM does not need to be refreshed andis fast relative to DRAM, but has lower density and is more expensiverelative to DRAM. Both SRAM and DRAM are volatile, meaning that if powerto the memory is interrupted the memory will lose the information storedin the memory cells.

Consequently, existing technologies are either non-volatile but are notrandomly accessible and have low density, high cost, and limited abilityto allow multiples writes with high reliability of the circuit'sfunction, or they are volatile and complicate system design or have lowdensity. Some emerging technologies have attempted to address theseshortcomings.

For example, magnetic RAM (MRAM) or ferromagnetic RAM (FRAM) utilizesthe orientation of magnetization or a ferromagnetic region to generate anonvolatile memory cell. MRAM utilizes a magnetoresistive memory elementinvolving the anisotropic magnetoresistance or giant magnetoresistanceof ferromagnetic materials yielding nonvolatility. Both of these typesof memory cells have relatively high resistance and low-density. Adifferent memory cell based upon magnetic tunnel junctions has also beenexamined but has not led to large-scale commercialized MRAM devices.FRAM uses a circuit architecture similar to DRAM but which uses a thinfilm ferroelectric capacitor. This capacitor is purported to retain itselectrical polarization after an externally applied electric field isremoved yielding a nonvolatile memory. FRAM suffers from a large memorycell size, and it is difficult to manufacture as a large-scaleintegrated component. More details are discussed in U.S. Pat. Nos.4,853,893; 4,888,630; and 5,198,994, the contents of which areincorporated by reference.

Another technology having non-volatile memory is phase change memory.This technology stores information via a structural phase change inthin-film alloys incorporating elements such as selenium or tellurium.These alloys are purported to remain stable in both crystalline andamorphous states allowing the formation of a bistable switch. While thenonvolatility condition is met, this technology appears to suffer fromslow operations, difficulty of manufacture and reliability and has notreached a state of commercialization. More details are discussed in U.S.Pat. Nos. 3,448,302; 4,845,533; 4,876,667; 6,044,008, the contents ofwhich are incorporated by reference.

Wire crossbar memory (MWCM) has also been disclosed in U.S. Pat. Nos.6,128,214; 6,159,620; and 6,198,655, the contents of which areincorporated by reference. These memory proposals envision molecules asbistable switches. Two wires (either a metal or semiconducting type)have a layer of molecules or molecule compounds sandwiched in between.Chemical assembly and electrochemical oxidation or reduction are used togenerate an “on” or “off” state. This form of memory requires highlyspecialized wire junctions and may not retain nonvolatility owing to theinherent instability found in redox processes. Memory devices have beenproposed which use nanoscopic wires, such as single-walled carbonnanotubes, to form crossbar junctions to serve as memory cells.Typically, individual single-walled nanotube wires suspended over otherwires define memory cells. Electrical signals are written to one or bothwires to cause them to physically attract or repel relative to oneanother. Each physical state (i.e., attracted or repelled wires)corresponds to an electrical state. Repelled wires are an open circuitjunction. Attracted wires are a closed state forming a rectifiedjunction. When electrical power is removed from the junction, the wiresretain their physical (and thus electrical) state thereby forming anon-volatile memory cell.

In a parallel trend, as discussed in United States Patent Application20030121764, nanowires are often thin strands of conductive orsemiconductive materials with diameters in the nanometer range to a fewhundred nanometers. The nanowires have been operated in aroom-temperature, ultraviolet lasing mode. These devices can convertelectrical energy into light energy. United States Patent Application20050009224 mentions the high cost of manufacturing conventional solarcells limits their widespread use as a source of power generation. Theconstruction of conventional silicon solar cells involves four mainprocesses: the growth of the semiconductor material, separation intowafers, formation of a device and its junctions, and encapsulation. Forcell fabrication alone, numerous steps are required to make the solarcell and many of these steps require high temperatures (300° C.-1000°C.), high vacuum or both. In addition, the growth of the semiconductorfrom a melt is at temperatures above 1400° C. under an inert argonatmosphere. To obtain high efficiency devices (>10%), structuresinvolving concentrator systems to focus sunlight onto the device,multiple semiconductors and quantum wells to absorb more light, orhigher performance semiconductors such as GaAs and InP, are needed.These options all result in increased costs.

Recently, advances in textile technology have resulted in improvedfabrics and textiles. For example, U.S. Pat. No. 6,821,936 disclosesthat silver-containing inorganic microbiocides can be utilized asantimicrobial agents on and within a plethora of different substratesand surfaces. In particular, such microbiocides have been adapted forincorporation within melt spun synthetic fibers in order to providecertain fabrics which selectively and inherently exhibit antimicrobialcharacteristics. Furthermore, attempts have been made to apply suchspecific microbiocides on the surfaces of fabrics and yarns with littlesuccess from a durability standpoint. A topical treatment with suchcompounds has never been successfully applied as a durable finish orcoating on a fabric or yarn substrate. Although such silver-based agentsprovide excellent, durable, antimicrobial properties, to date such isthe sole manner available within the prior art of providing along-lasting, wash-resistant, silver-based antimicrobial textile.However, such melt spun fibers are expensive to make due to the largeamount of silver-based compound required to provide sufficientantimicrobial activity in relation to the migratory characteristics ofsuch a compound within the fiber itself to its surface. A topicalcoating is also desirable for textile and film applications,particularly after finishing of the target fabric or film.

Such a topical procedure permits treatment of a fabric's individualfibers prior to or after weaving, knitting, and the like, in order toprovide greater versatility to the target yarn without altering itsphysical characteristics. Such a coating, however, must prove to be washdurable, particularly for apparel fabrics, in order to be functionallyacceptable. Furthermore, in order to avoid certain problems, it ishighly desirable for such a metallized treatment to be electricallynon-conductive on the target fabric, yarn, and/or film surface. The '936patent applies a treatment with silver ions, particularly asconstituents of inorganic metal salts or zeolites in the presence of aresin binder, either as a silver-ion overcoat or as a component of a dyebath mixture admixed with the silver-ion antimicrobial compound.

United States Patent Application 20040142168 discloses fibers, andfabrics produced from the fibers, are made water repellent,fire-retardant and/or thermally insulating by filling void spaces in thefibers and/or fabrics with a powdered material. When the powder issufficiently finely divided, it clings to the fabric's fibers and toitself, resisting the tendency to be removed from the fabric.

SUMMARY

In one aspect, an apparatus includes a first array of transistorelements; a second array of carbon nano-elements formed above or belowthe first array of transistor elements; and a circuit coupled to thefirst array to access the carbon nano elements.

In another aspect, systems and methods are disclosed for forming ananowire data storage device. In one embodiment, a memory deviceincludes a first array of nano-scale memory elements; and a decodercoupled to the first array to select one of the nano-scale memoryelements. In another embodiment, an array of deformable nanowires isactivated and/or sensed by a multidimensional read/write head. In otherembodiments, a non-volatile, nanoscale memory array is provided. In oneembodiment, an electronic memory cell uses at least one organic singlemolecule memory (SMM) in combination with a switch element (such as atransistor). Arranging these memory cells into rows and columns forms amemory array. Peripheral access circuitry allows individual addressingcapability for each of the electronic memory cells. The access circuitryis fabricated from semiconductor elements. The electronic memory arrayuses an array of nanowires formed above an array of electrodes. Thememory cells in the array are addressed either serially or in parallelby using appropriate read/write access techniques. Different redundanttechniques are used to minimize losses due to defective cells in the rowor column of the memory array.

In another aspect, systems and methods are disclosed for forming ananowire data storage device. In one embodiment, a memory deviceincludes a first array of nano-scale memory elements; and a decodercoupled to the first array to select one of the nano-scale memoryelements. In another embodiment, an array of deformable nanowires isactivated and/or sensed by a multidimensional read/write head.

Advantages of the data storage devices may include one or more of thefollowing. The data storage devices have high density, low powerconsumption, non-volatility and high speed.

In one aspect, an apparatus includes a plurality of wash durableclothing strands; an array of nano electronic elements fabricated in thestrands; and an array of memory elements coupled to the nano electronicelements. The nano electronic elements can include solar cells, displayelements, or antennas, among others.

In another aspect, nanowires emit light as well as convert light intoelectrical energy. The array includes a first portion of lightharvesting molecules operating with a second portion of light emittingmolecules. In one implementation, the first and second portions arepositioned side by side. In yet another implementation, the firstportion can be transparent and positioned on top. In yet anotherimplementation, the second portion is transparent and positioned abovethe first position. The array of light harvesting and light emittingmolecules generate electricity when light is available and illuminateduring periods of darkness.

In one implementation, the nanowires are used as a computer displayscreen so that the display generates power while it is rendering imageson the screen. In another implementation, the nanowires are used tocapture and convert light energy into electrical energy stored in abattery so that the energy can be used to power the nanowires for lightemission at night.

Advantages of the light emitting/conversion aspect may include one ormore of the following. The system emits light without requiring externalpower when sunlight is shining on the unit. The system effectivelycombines multiple components required to generate power and light into asingle integrated circuit device. The complete integration of componentsgreatly reduces manufacturing costs. The system provides for fast, easymigration of existing designs to high performance, high efficiencysingle chip solutions.

In yet another aspect, a method is set forth for forming a flexibleelectrically conducting nanowire cloth. The method comprises contactingsubstantially the entire surfaces of a plurality of intermingled orinterwoven fibers of a nano material.

Implementations of the nanowire cloth aspect may include one or more ofthe following. The nanowires can form data storage devices such asmemory arrays, light emitting or light conversion devices, or energyconversion devices. The fibers can be covered with a coating thatexhibits a sheet resistance which lies between about 0.1 ohm per squareand about 1,000 ohms per square. Such coated fibers can be used asantenna materials as well.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic of an exemplary single molecule memoryarray.

FIG. 2 illustrates an exemplary single molecule memory cell.

FIG. 3 illustrates the addressing logic for certain memory embodiments.

FIG. 4 illustrates a nanowire crossbar memory array according to certainembodiments of the invention.

FIG. 5A-B illustrate the two states of the exemplary nanowire crossbarmemory array of FIG. 4.

FIG. 6 illustrates a parallel read-write embodiment.

FIG. 7 shows a cross-sectional view of a portion of a substrate made upof strands of smaller fibers.

DETAILED DESCRIPTION

FIG. 1 illustrates a schematic of a single molecule memory arrayaccording to certain embodiments of the invention. An array 100 isformed by arranging a plurality of memory elements 101 into rows andcolumns. These memory elements can be either in an ON state or an OFFstate, depending on their voltage and current conditions. Each memoryelement consists of a single molecule memory (SMM) 102 in combinationwith a gate or switch 103.

In one embodiment, conventional DRAM cells are fabricated, and then theSMMs 102 are formed above the conventional DRAM cells. In anotherembodiment, in the final stages of DRAM fabrication, DRAM capacitor arenot formed and in lieu thereof SMM elements are formed usingspin-coating techniques so that there is only one layer of nano memoryelements. The memory elements can be addressed through parallel lines ofwires 104 in communication with electrodes. The system is fabricated ona silicon substrate and the cells can be electrically isolated from oneanother using insulators like silicon nitride or silicon oxide grown andpatterned on the silicon wafers.

Another embodiment uses a stacked DRAM cell organization where, due tosmall size of SMM, a plurality of standard DRAM cells each having oneport to attach to one SMM can be vertically stacked into the same cellso that after spin coating each of the SMMs only self-assembles to oneport on the stacked memory cell. Stacking can be done since the SMMsrequire much less space than comparable capacitors). The SMMsself-assemble to attach only to the port during spin-coating.

FIG. 2 illustrates the SMM cell according to certain embodiments of theinvention. The individual memory cell consists of a switch 105, such asa MOSFET, connected to an SMM 106. The MOSFET is made from a siliconsubstrate and. In one embodiment, rests above a conventional DRAMcapacitor cell structure 107, while in a second embodiment, theconventional DRAM capacitor cell structure is not fabricated (empty) andthe structure 107 may be non-functional silicon or other suitablematerials. The MOSFET has two doped regions connected to the source anddrain electrodes 108-109 and a gate dielectric on top of which rests apolysilicon or metal gate 110 connected to a gate electrode (not shown).The spacers 111-112, which isolate the gate from the source and drainelectrodes, are made of silicon oxide or nitride or a combination of thetwo. The entire structure is insulated using a dielectric like siliconoxide 113. Instead of using a capacitor like in the case of aconventional DRAM cell, the SMMs can be deposited on the electrode usingone of several organic film deposition techniques likeelectropolymerization, solution-processed deposition, vacuumevaporation, screen printing, or Langmuir-Blodgett technique. Onepreferred technology uses spin-coating techniques to realize ahomogenous films in the last step of fabrication. In spin-coating, anorganic material is dropped onto the wafer surface which is then spun atseveral revolutions per minute to uniformly coat the surface. The RPMdetermines the uniformity and thickness of the spin-coated organicdevice. After spin-coating, using predetermined thermodynamicconditions, the SMMs can selectively self-assemble only at the outputport of the access transistor. The thermodynamic driving force forself-assembly could come about by the different interactions between apart of the molecule and the electrodes, the molecules themselves or acombination of the two. The relatively simple, low temperature andlow-cost process can be easily performed at the end of the transistorfabrication process.

Redundant techniques are applied to minimize losses due to defectivecells in the row or column of memory. While the nature of the datastorage in the SMM is not important for the functioning of the memoryarray, the data manifests itself in the form of current or voltagechange, which can then be read out through the wires. The data can bestored in the SMMs in various forms, such as, a red-ox state of amolecule, a physical deformation of the molecule or even simply chargestored across a SMM capacitor. The data can be written into the SMMcells through parallel wires, which are then electrically connected toelectrodes.

FIG. 3 illustrates exemplary addressing logic for certain embodiments.The architecture consists of all the elements of the memory cellconnected through wires in rows and columns to form a memory array 115.The wires are then connected to a set of electrodes, which interface thememory array to the input/output system. The electrodes and wiresarranged in rows are the word lines and the electrodes and wiresarranged in columns are the bit lines. Each individual memory elementcan be selected by a combination of voltages and currents applied acrossthe bit lines and the word lines. An as exemplary case, when the n^(th)word line is high and the m^(th) bit line is high, then the (m,n)^(th)element in the array can be selected out of the entire array to bewritten into or read out from. The bit lines and word lines arecontrolled by control logic 116 which sends out the information toselect a particular memory element to the word and bit line. The wordand bit line decoders decode 117 this information and convert it into aset of voltages or currents, which drive the electrodes of the memoryarray to select out a single element from the array. The output of theselected memory element can then be read out of an output buffer 118.The control logic, the decoders/drivers and the output buffer are allfabricated using standard semiconductor elements.

FIG. 4 illustrates a nanowire crossbar memory 119 array according toanother memory embodiment. In this embodiment, nanoscale memorystructures are implemented instead of the standard DRAM cell structure.In these embodiments, an array of nanowires 120 is formed above an arrayof electrodes 121. The number of memory elements present in the array isfor illustrative purposes only. The memory elements can be addressedthrough parallel lines of wires in communication with electrodes. Duringoperation, when a voltage is applied to the appropriate row/column, thenanowire deforms at the intersection of a row/column where a voltage isapplied. The deformation causes the nanowire to short to either groundor VDD. The memory is non-volatile and operates at high speed. Theentire architecture is fabricated on a silicon substrate. In oneembodiment, the nano-cell can be electrical isolated from one anotherabove conventional DRAM cell 122. Alternatively, the cells can beelectrical isolated from one another using dielectric materials such assilicon oxide.

FIGS. 5A-B illustrate the two states of the nanowire crossbar memoryarray according to certain embodiments of the invention. The memoryelement consists of at least a single nanowire 123 bridged between twoelectrodes 124 and a third bottom electrode 125, which controls thedeformation of the nanowire. When the nanowire is in the ‘0’ state 126,the wire rests in its neutral state and does not have any deformationassociated with it. As a result, it is electrically isolated from thebottom electrode since it does not contact it. However, when a voltageis applied to the bottom electrode, it attracts the nanowire causing itto deform and eventually contact and short the nanowire to apredetermined voltage such as ground or Vdd. In this state, due to theforces of interaction—Van der Waals forces—between the nanowire and thebottom electrode 125, the nanowires 123 remains contacted with theelectrode 125 even after the applied bias is removed. This is the ‘1’state 127 of the memory element.

In one embodiment, the memory cell may be fabricated by patterningparallel conducting wires 123 on an insulating dielectric 128 that maybe grown or deposited on a silicon substrate 129, which may include aconventional DRAM cell therein and the memory cell can be formed abovethe conventional DRAM cell. A matted layer of nanowires can then begrown or deposited on top of these metallic electrodes to form bridgesof nanowires suspended between two electrodes 123. The nanowires may bepatterned to control the density of the nanowires in a particularlocation. One or more nanowires may be used to form a bridge between thebottom electrodes in one cell.

The SMM organic memory array uses dedicated nanoscale wires to provideredundancy to overcome breakage of wires during processing. In oneembodiment, the redundant wires are simply formed over the electrodesand if one of the wires is broken, the remaining wires provide theredundant coverage. In one implementation, each wire is tested against aknown input and the wire that passes all memory test procedures isselected as the valid wire.

In another embodiment, each wire “votes” when the memory cell isqueried, and the value of a majority of concurring outputs wins (forexample, in a cell with seven wires, if four wires vote for a particularvalue, then the output is that value. This embodiment providesredundancy needed for military or space applications where reliabilityis important.

In yet another embodiment, a 2D array of nanowires can form a cross-barconfiguration for logic and memory devices thereon. Current control inthe nanowires or nanotube is exerted using gates or by forming diodejunctions. FET behavior is achieved using metallic gates and crossingnanowires or nano-tubes. By varying the amount of oxide grown at theirintersection, crossing nanowires or nanotubes can be made such that onenanowire forms a diode with the other, or one acts as a FET gate to theother. The SMM can be attached to the 2D array to provide data storagecapacity in addition to the logic gates. However, such 2D array ofnanowires that provide logic and memory capacity, the nanowires canfail. To maximize yield, redundancy is used as numerous nanowires can befabricated at once.

In one embodiment, software during testing identifies broken nanowiresand specifies a replacement routing over redundant nanowires using alearning machine such as a neural network, perceptron, or anyself-organized network of nano memory elements to deselect defectivememory elements. In one implementation, the neural network learns usinggenetic algorithms where the weights and biases of all the neurons arejoined to create a single vector. A certain set of vectors is a correctsolution to the classification of defective, broken or otherwisenon-functional nanowires and to reroute the connections to functioningor “fit” nanowires. In this implementation, the process is as follows:

-   -   choose initial population of nanowires    -   evaluate each individual nanowire's fitness    -   repeat        -   select individual nanowires        -   mate nanowires pairs at random        -   apply crossover operator        -   apply mutation operator        -   evaluate each individual nanowire's fitness    -   until terminating condition

The learning loop can terminate either if a satisfactory solution isfound, or the number of generations pass a preset limit, suggesting thata complete solution will not be found with this set of individuals.

In our case, we have several separated populations, all of which evolveseparately. Once every several generations, the process allowscross-over from different populations of nanowires.

In yet another embodiment, instead of having binary states 126 and 127as shown in FIGS. 5A and 5B, the memory element can store a plurality ofvalues based on the degree of coupling of the wire 123 to the electrode125. In one embodiment, the electrode 125 can deform the wire 123 in 256steps. In another implementation, the electrode 125 can provide voltages(or currents) that have 256 discrete values. The number of steps ordiscrete values is exemplary, and the device can have more or less stepsor discrete values. In yet another implementation, the SMM storesphotons or light charges and such an array can act as an imager forcamera or imaging applications.

In one implementation, the nanowires form neural networks with learningcapability. Artificial neural networks have inter-connected units whichserve as model neurons. The synapse is modeled by a modifiable weightassociated with each particular connection. For a neural network toperform a specific task the connection between units must be specifiedand the weights on the connections must be set appropriately. Theconnections determine whether it is possible for one unit to influenceanother. The weights specify the strength of the influence. In thisimplementation, the weights are stored in the SMM. The artificialnetworks express the electrical output of a neuron as a single numberthat represents the rate of firing. Each unit converts the pattern ofincoming activities that it receives into a single outgoing activitythat it sends to other units. This conversion is performed in twosteps: 1) it multiplies each incoming activity by the weight on theconnection and adds together all these weighted inputs to get a totalinput; 2) the unit uses an input output function that transform thetotal input into an outgoing activity. The global behavior of anartificial neural network depends on both the weight and theinput-output function that is specified for the unit. This functiontypically falls into one of three categories: linear, threshold orsigmoid. For linear units, the output activity is proportional to thetotal weighted input—For threshold units the output is set at one of twolevels, depending on whether the total input is greater than, or lessthan some threshold value. In sigmoid units, the output variescontinuously but not linearly as the input changes. Sigmoid units bear agreater resemblance to real neurons than linear or threshold units.

In one implementation, the artificial neural network consists of threegroups or layers of units. An input layer is connected to a layer ofintermediate units (called hidden units), which is in turn connected toa layer of output units. The activity of the input units represents theincoming external information that is fed into the network. The activityof each hidden unit is determined by the activities of the input unitsand the weights on the connections between the input and hidden units.The behavior of the output units depends in turn, on the activity of thehidden units and the weights between the hidden and output units. Thehidden units are free to construct their own representation of theinput. The weights between the input and hidden units determine wheneach hidden unit is active. By modifying these weights a hidden unit canchoose what it represents.

The three layer network can be trained as follows: first the network ispresented with a training example consisting of a pattern of activitiesfor the input units together with the pattern that represents thedesired output. Then it is determined how closely the actual outputmatches the desired output. Next the weight of each connection ischanged in order to produce a better approximation of the desiredoutput.

FIG. 6 illustrates the parallel read-write technique according to someembodiments of the invention. In yet another embodiment of the nanowirememory array, instead of using row and column decoders, an array ofdeformable nanowires is formed on a substrate and a multi-dimensionalread/write head 130 causes the wires to deform. The head 130 operates inparallel and can write 256, 512, 1024, and 2048 bits at a time. In thisimplementation, the head 130 is advantageously used as a voltage ormechanical probe, which in turn is activated by a current flowingthrough it or a voltage applied to it. When the head is used as avoltage probe, a voltage appearing at the end of the probe appearsacross the nanowire, causing the nanowire to either switch to a ‘1’state or a ‘0’ state. The head can also be used to read out the state ofthe memory cell by applying a new voltage across the electrodes andmeasuring the current flowing through them between them withoutdisturbing the state of the nanowire in the cell, thus maintainingnon-volatility. The individual cantilever voltage probes are controlledthrough a multiplexer-driver circuit 131 made from standardsemiconductor elements, which determine the voltage appearing acrosseach of the probes and hence the data that should be written by thetwo-dimensional head. The main advantage of this type of read-writetechniques is the ability to write a large number of bits at the sametime, thus speeding up the memory access time. In other embodiments, thehead can have m by n probes (2 dimensional head) and in yet otherembodiments, the head can have m by n by probes (3 dimensional head).

In another aspect, a power producing solar cell is made usingnano-wires. In one embodiment, the first portion includes excitonicsolar cells including organic, hybrid organic/inorganic anddye-sensitized cells with a thick nanoparticle film that provides alarge surface area for the adsorption of light-harvesting molecules. Thenanowires can be used in conjunction with existing LCD displays. Oneembodiment uses a reduced version of standard LCD cell-layout andfabrication, except a final processing step coats the LCD with thenanowires using spin-coating process. The nanowires self-assemble toattach only to designated spots in the LCD array during spin-coating.Conventional LCD manufacturing techniques are used until the last stepof spin-coating the nanowires onto the LCD cell organization where thenanowires can self-assemble into the display array. Redundant techniquesare applied to minimize losses due to defective cells in the row orcolumn of the display. Variations of nanowires can be used. For example,only light harvesting nanowires can be spin coated onto the LCD cells,or alternatively only light emitting nanowires can be spin coated ontothe LCD cells, or alternatively both light harvesting and emittingnanowires are spin-coated onto the LCD wafer. In another implementation,the array can be made from flexible materials such as plastics and canbe used as a housing for other electronics such as processor and memoryembedded therein.

In yet another embodiment, the array can be attached to a wall to lightup a room or be placed on a floor or ceiling to illuminate a pathway orto accentuate certain features of a house. In yet other embodiment, thearray can be embedded into furniture.

In another embodiment, the nanowires can be embedded in a strand ofclothing to provide wearable electronic devices. FIG. 7 shows across-sectional view of a portion of a substrate made up of strands ofsmaller fibers 10. The smaller single fiber strands 10 can be eithersmall porous or non-porous fiber strands. The porous fiber strands canhave individual voids 20 and 22. The smaller single fiber strands can beeither small porous or non-porous fiber strands. The porous fiberstrands can have individual voids. Some of the voids are at leastpartially filled with particles in the size range below 100 nm. Voidvolumes can also exist between the smaller single porous or non-porousfiber strands and a portion of the void volume is at least partiallyfilled with particles in the size range of less than 100 nm. In oneembodiment, the voids are provided with a composition havingnano-particles. The voids contain first nano-particles that wick upmoisture from the user's skin, the voids contain second nano-particlesthat repel rain from the fabric, and the voids can contain electronicdevices such as data storage devices, light capture or light emissiondevices and energy storage devices. The substrate includes fibers, wovenand non-woven fabrics derived from natural or synthetic fibers or blendsof such fibers, as well as cellulose-based papers, and the like. Theycan include fibers in the form of continuous or discontinuousmonofilaments, multifilaments, staple fibers, and yarns containing suchfilaments and/or fibers, which fibers can be of any desired composition.The fibers can be of natural, manmade, or synthetic origin. Mixtures ofnatural fibers, manmade fibers, and synthetic fibers can also be used.Examples of natural fibers include cotton, wool, silk, jute, linen, andthe like. Examples of man-made fibers include regenerated celluloserayon, cellulose acetate and regenerated proteins. Examples of syntheticfibers include polyesters (including polyethyleneterephthalate andpolypropyleneterephthalate), polyamides (including nylon), acrylics,olefins, aramids, azlons, modacrylics, novoloids, nytrils, aramids,spandex, vinyl polymers and copolymers, vinal, vinyon, Kevlar®, and thelike.

The nanosize particles form projections on the outside or sheath of thesmaller fibers and the single fiber. The available void spaces in thefibers and between strands of smaller fibers are filled with ananoporous material. In one embodiment, silver particles are distributedevenly or unevenly along the length of the strand or fiber.Nano-particles such as silver, gold, aluminum, or similar particles canbe used. The nano-particles can be obtained by chemical techniques suchas reduction, or non chemical techniques such as laser treatment ormechanical ablation from a solid. The reflecting particles can be coatedwith a surfactant. The nano-particles impart to the fabric/textile oneor more of the cleaning, insulating, waterproofing, and fire resistantproperties. Fibers and fabrics produced from the fibers are made waterrepellent, dirt repellant, fire-retardant and/or thermally insulating byfilling the void spaces in the fibers and/or fabrics with a finelypowdered material. The particles can be a nanoporous material, ananoporous powdered material, a solgel derived material, an aerogel-likematerial, an aerogel, an insulating material, a thermally insulatingmaterial, a water repellant material, a hydrophobic material, a waterrepellant material, a hydrophobic material, a hydrophobic silicaaerogel, a fire resistant material, or a mixture of the foregoingmaterials. The substrate can be one of: an individual yarn, a textile, afabric, or a film. The nano-particles can be an antimicrobial compound,a fireproofing compound, an insulating compound, or an anti-odorcompound. The nano-particles can be a metal such as silver, gold,aluminum, or any suitable metals. The nano-particles can also be anon-metal. The projections are self-assembled. Each strand can have afirst portion to absorb water and a second portion to repel water. Thefirst portion wicks moisture from skin and the second portion repelsmoisture from the material. The nano-particles can contract at apredetermined temperature, or expand at a predetermined temperature. Thenano-particles can be applied to the substrate containing the strands bysoaking, spin casting, dipping, fluid-flow, padding, or spraying asolution containing the nano-particles on the substrate. Next, thesubstrate with the nano-particles is dried. In one embodiment, thedrying occurs at room temperature, thus facilitating manufacturing andminimizes costs while being environmentally friendly.

Since the nano-particles are embedded in the strand, they are secured tothe fabric or textile material. The nano-particles substantially remainafter the substrate is washed at least 40 times in accordance with thewash procedure of AATCC Test Method 130-1981. For example, at least 80%of the nano-particles remain after the substrate is washed at least 40times in accordance with the wash procedure of AATCC Test Method130-1981. The nano-particles can be applied to natural (cotton, wool,and the like) or synthetic fibers (polyesters, polyamides, polyolefins,and the like) as a substrate, either by itself or in any combinations ormixtures of synthetics, naturals, or blends or both types. As for thesynthetic types, for instance, and without intending any limitationstherein, polyolefins, such as polyethylene, polypropylene, andpolybutylene, halogenated polymers, such as polyvinyl chloride,polyesters, such as polyethylene terephthalate, polyester/polyesters,polyamides, such as nylon 6 and nylon 6,6, polyurethanes, as well ashomopolymers, copolymers, or terpolymers in any combination of suchmonomers, and the like, may be utilized. Nylon 6, Nylon 6,6,polypropylene, and polyethylene terephthalate (a polyester) areparticularly preferred. Additionally, the target fabric may be coatedwith any number of different films, including those listed in greaterdetail below. Furthermore, the substrate may be dyed or colored toprovide other aesthetic features for the end user with any type ofcolorant, such as, for example, poly (oxyalkylenated) colorants, as wellas pigments, dyes, tints, and the like. Other additives may also bepresent on and/or within the target fabric or yarn, including antistaticagents, brightening compounds, nucleating agents, antioxidants, UVstabilizers, fillers, permanent press finishes, softeners, lubricants,curing accelerators, and the like. Soil release agents can be used toprovide hydrophilicity to the surface of polyester. With such a modifiedsurface, again, the fabric imparts improved comfort to a wearer bywicking moisture. In one embodiment, the nano-particles can includecopolymers containing a fluorinated monomer, an alkyl monomer, areactive monomer (e.g., hydroxyethylmethacrylate, N-methylolacrylamide), and various other auxiliary monomers (e.g. vinylidenechloride, polyethylene glycol methacrylate, etc.) that impart water andoil repellent finish to textiles. In yet other embodiments, thenano-particles can include stain-releasing finish with an acrylatecopolymer emulsion, an aminoplast resin, a resin catalyst, or polymersthat contain carboxyl groups, salts of carboxyl groups. In anotherembodiment that achieves wrinkle resistance for cotton substrates, thenano-particles can include alcohol groups on adjacent cellulose chains.The nanoparticles are partially crosslinked to keep the chains fixedrelative to each other. Crosslinking agents (resins) for durable-pressproperties include isocyanates, epoxides, divinylsulfones, aldehydes,chlorohydrins, N-methylol compounds, and polycarboxylic acids. Inanother aspect, the nano-particles can include Fullerene molecularwires. In one embodiment, the bonding wires can be FSAs or self-assemblyassisted by binding to FSA or fullerene nano-wires. Choice of FSAs canalso enable self-assembly of compositions whose geometry imparts usefulchemical or electrochemical properties including operation as a catalystfor chemical or electrochemical reactions, sorption of specificchemicals, or resistance to attack by specific chemicals, energy storageor resistance to corrosion. Examples of biological properties of FSAself-assembled geometric compositions include operation as a catalystfor biochemical reactions; sorption or reaction site specific biologicalchemicals, agents or structures; service as a pharmaceutical ortherapeutic substance; interaction with living tissue or lack ofinteraction with living tissue; or as an agent for enabling any form ofgrowth of biological systems as an agent for interaction withelectrical, chemical, physical or optical functions of any knownbiological systems.

FSA assembled geometric structures can also have useful mechanicalproperties which include but are not limited to a high elastic tomodulus weight ratio or a specific elastic stress tensor. Self-assembledstructures, or fullerene molecules, alone or in cooperation with oneanother (the collective set of alternatives will be referred to as“molecule/structure”) can be used to create devices with usefulproperties. For example, the molecule/structure can be attached byphysical, chemical, electrostatic, or magnetic means to anotherstructure causing a communication of information by physical, chemical,electrical, optical or biological means between the molecule/structureand other structure to which the molecule/structure is attached orbetween entities in the vicinity of the molecule/structure. Examplesinclude, but are not limited to, physical communication via magneticinteraction, chemical communication via action of electrolytes ortransmission of chemical agents through a solution, electricalcommunication via transfer of electronic charge, optical communicationvia interaction with and passage of any form with biological agentsbetween the molecule/structure and another entity with which thoseagents interact.

The nanowires in the strands can also act as antennas. For example, thelengths, location, and orientation of the molecules can be determined byFSAs so that an electromagnetic field in the vicinity of the moleculesinduces electrical currents with some known phase relationship withintwo or more molecules. The spatial, angular and frequency distributionof the electromagnetic field determines the response of the currentswithin the molecules. The currents induced within the molecules bear aphase relationship determined by the geometry of the array. In addition,application of the FSAs could be used to facilitate interaction betweenindividual tubes or groups of tubes and other entities, whichinteraction provides any form of communication of stress, strain,electrical signals, electrical currents, or electromagnetic interaction.This interaction provides an “interface” between the self-assembled NANOstructure and other known useful devices. In forming an antenna, thelength of the NANO tube can be varied to achieve any desired resultantelectrical length. The length of the molecule is chosen so that thecurrent flowing within the molecule interacts with an electromagneticfield within the vicinity of the molecule, transferring energy from thatelectromagnetic field to electrical current in the molecule to energy inthe electromagnetic field. This electrical length can be chosen tomaximize the current induced in the antenna circuit for any desiredfrequency range. Or, the electrical length of an antenna element can bechosen to maximize the voltage in the antenna circuit for a desiredfrequency range. Additionally, a compromise between maximum current andmaximum voltage can be designed. A Fullerene NANO tube antenna can alsoserve as the load for a circuit. The current to the antenna can bevaried to produce desired electric and magnetic fields. The length ofthe NANO tube can be varied to provide desired propagationcharacteristics. Also, the diameter of the antenna elements can bevaried by combining an optimum number of strands of NANO tubes. Further,these individual NANO tube antenna elements can be combined to form anantenna array. The lengths, location, and orientation of the moleculesare chosen so that electrical currents within two or more of themolecules act coherently with some known phase relationship, producingor altering an electromagnetic field in the vicinity of the molecules.This coherent interaction of the currents within the molecules acts todefine, alter, control, or select the spatial, angular and frequencydistributions of the electromagnetic field intensity produced by theaction of these currents flowing in the molecules. In anotherembodiment, the currents induced within the molecules bear a phaserelationship determined by the geometry of the array, and these currentsthemselves produce a secondary electromagnetic field, which is radiatedfrom the array, having a spatial, angular and frequency distributionthat is determined by the geometry of the array and its elements. Onemethod of forming antenna arrays is the self-assembly monolayertechniques discussed above.

Various molecules or NANO-elements can be coupled to one or moreelectrodes in a layer of an IC substrate using standard methods. Thecoupling can be a direct attachment of the molecule to the electrode, oran indirect attachment (e.g. via a linker). The attachment can be acovalent linkage, an ionic linkage, a linkage driven by hydrogen bondingor can involve no actual chemical attachment, but simply a juxtapositionof the electrode to the molecule. In one embodiment, a “linker” is usedto attach the molecule(s) to the electrode. The linker can beelectrically conductive or it can be short enough that electrons canpass directly or indirectly between the electrode and a molecule of thestorage medium. The manner of linking a wide variety of compounds tovarious surfaces is well known and is amply illustrated in theliterature. Means of coupling the molecules will be recognized by thoseof skill in the art. The linkage of the storage medium to a surface canbe covalent, or by ionic or other non-covalent interactions. The surfaceand/or the molecule(s) may be specifically derivatized to provideconvenient linking groups (e.g. sulfur, hydroxyl, amino, etc.). In oneembodiment, the molecules or NANO-elements self-assemble on the desiredelectrode. Thus, for example, where the working electrode is gold,molecules bearing thiol groups or bearing linkers having thiol groupswill self-assemble on the gold surface. Where there is more than onegold electrode, the molecules can be drawn to the desired surface byplacing an appropriate (e.g. attractive) charge on the electrode towhich they are to be attached and/or placing a “repellant” charge on theelectrode that is not to be so coupled.

The FSA bonding wires can be used alone or in conjunction with otherelements. A first group of elements includes palladium (Pd), rhodium(Rh), platinum (Pt), and iridium (Ir). As noted in US Patent ApplicationSerial No. 20030209810, in certain situations, the chip pad is formed ofaluminum (Al). Accordingly, when a gold-silver (Au—Ag) alloy bondingwire is attached to the chip pad, the Au of the bonding wire diffusesinto the chip pad, thereby resulting in a void near the neck. Thenano-bonding wire, singly or in combination with the elements of thefirst group form a barrier layer in the interface between a Au-richregion (bonding wire region) and an Al-rich region (chip pad region)after wire bonding, to prevent diffusion of Au and Ag atoms, therebysuppressing intermetallic compound and Kirkendall void formation. As aresult, a reduction in thermal reliability is prevented.

Nano-wires can also be used singly or in combination with a second groupof elements that includes boron (B), beryllium (Be), and calcium (Ca).The elements of the second group enhances tensile strength at roomtemperature and high temperature and suppresses bending or deformationof loops, such as sagging or sweeping, after loop formation. When anultra low loop is formed, the elements of the second group increaseyield strength near the ball neck, and thus reduce or prevent a ruptureof the ball neck. Especially, when the bonding wire has a smalldiameter, a brittle failure near the ball neck can be suppressed.Nano-bonding wires can also be used singly or in combination with athird group of elements that includes phosphorous (P), antimony (Sb),and bismuth (Bi). The elements of the third group are uniformlydispersed in an Au solid solution to generate a stress field in the goldlattice and thus to enhance the strength of the gold at roomtemperature. The elements of the third group enhance the tensilestrength of the bonding wire and effectively stabilize loop shape andreduce a loop height deviation.

Nano-bonding wires can also be used singly or in combination with afourth group of elements that includes magnesium (Mg), thallium (TI),zinc (Zn), and tin (Sn). The elements of the fourth group suppress thegrain refinement in a free air ball and soften the ball, therebypreventing chip cracking, which is a problem of Au—Ag alloys, andimproving thermal reliability.

The nano-bonding wires provide superior electrical characteristics aswell as mechanical strength in wire bonding applications. In a wirebonding process, one end of the nano bonding wire is melted bydischarging to form a free air ball of a predetermined size and pressedon the chip pad to be bound to the chip pad. The electronics can beembedded inside clothing made from the nano-fabric or textile. Thetextile/fabric substrate can interconnect a number of other chips. Forexample, in a plastic flexible clothing substrate, a solar cell ismounted, printed or suitably positioned at a bottom layer to capturephotons and convert the photons into energy to run the credit cardoperation. Display and processor electronics are then mounted or on theplastic substrate. A transceiver chip with nano antennas is also mountedor printed on the plastic substrate. The nano antenna can be thenano-particles embedded into the strands of the fabric/textilesubstrate. The nanowires in the strands can also function asinterconnections to connect one electronic device to another device onthe clothing. In addition to interconnect, antenna and solar cells,other nano-particle components can be embedded into the fabric ortextile such as sensors, data storage devices, memory and othersdisclosed in commonly-owned, copending application Ser. No. 11/064,363,the content of which is incorporated by reference.

In one embodiment, nano-sensors are mounted on a user's clothing. Forexample, sensors are woven into a single-piece garment (an undershirt)on a weaving machine. An optical fiber is integrated into the structureduring the fabric production process without any discontinuities at thearmhole or the seams. A nano-interconnection bus transmits informationfrom (and to) sensors mounted at any location on the body thus creatinga flexible “bus” structure. The strands or fibers serve as a data bus tocarry the information from the sensors (e.g., EKG sensors) on the body.The sensors provide data to the interconnection bus and at the other endsimilar T-Connectors will be used to transmit the information tomonitoring equipment or personal status monitor. Since shapes and sizesof humans will be different, sensors can be positioned on the rightlocations for all patients and without any constraints being imposed bythe clothing. Moreover, the clothing can be laundered without any damageto the sensors themselves.

The above description and drawings are only illustrative of preferredembodiments which achieve the features and advantages of the presentinvention, and it is not intended that the present invention be limitedthereto. The substrates can be used in a variety of ways including, butnot limited to various articles of clothing, including informalgarments, daily wear, workwear, activewear and sportswear, especiallythose for, but not limited to easily wet or stained clothing, such asformal garments, coats, hats, shirts, pants, gloves, and the like; otherfibrous substrates subject to wetting or staining, such as interiorfurnishings/upholstery, carpets, awnings, draperies, upholstery foroutdoor furniture, protective covers for barbecues and outdoorfurniture, automotive and recreational vehicle upholstery, sails forboats, and the like.

Any modification of the present invention which comes within the spiritand scope of the following claims is considered part of the presentinvention.

1. A nano device, comprising: a. a first array of transistor elements;b. a second array of carbon nano-elements formed above or below thefirst array of transistor elements; and c. a circuit coupled to thefirst array to access the carbon nano elements.
 2. The device of claim1, wherein the carbon nano elements are applied using a spin-coatingtechnique.
 3. The device of claim 1, comprising redundant carbon nanoelements to replace defective elements.
 4. The device of claim 3,wherein the redundant carbon nano elements are tested and each faultyelement is deselected prior to operation.
 5. The device of claim 3,wherein the carbon nano memory elements self-organize to selectfunctional elements and deselect defective elements.
 6. The device ofclaim 3, wherein the nano memory elements comprise a neural network todetect defective elements using genetic algorithm.
 7. The device ofclaim 1, wherein data is stored in one of: a red-ox state, a physicaldeformation of the nano memory element, a charge stored across the nanomemory element.
 8. The device of claim 1, comprising anano-electro-mechanical system (NEMS).
 9. The device of claim 1, whereinthe element comprises a nanowire positioned above an electrode that,when actuated, performs one of: deforming the nanowire, flattening thenanowire, attaches the wire to the electrode, repels the wire away fromthe electrode.
 10. The device of claim 1, comprising nano-wires forminga two-dimensional (2D) nano-scale crossbar.
 11. The device of claim 1,comprising light harvesting nanowires to capture solar energy or antennananowires to capture electromagnetic energy.
 12. The device of claim 1,comprising an energy storage device coupled to the light harvestingnanowires.
 13. The device of claim 1, comprising light emittingnanowires.
 14. The device of claim 1, comprising an energy storagedevice coupled to the light emitting nanowires.
 15. The device of claim1, comprising a wash durable strand of clothing containing the elements.16. An apparatus, comprising: a. a plurality of wash durable clothingstrands; and b. an array of nano electronic elements fabricated in thestrands.
 17. The apparatus of claim 16, wherein the nano electronicelements comprises one of: light emitting nanowires, light harvestingnanowires, an energy storage device, an antenna.
 18. The apparatus ofclaim 16, comprising a processor coupled to the elements.
 19. Theapparatus of claim 16, wherein the nano-electronic elements form anoptical interconnect in the clothing strands.
 20. A nano device,comprising: a wash durable material including a substrate having strandswith void spaces in the strands and between the strands; andnano-particles filling at least a part of the void spaces and formingone or more projections on the substrate, wherein the projections resistdirt from attaching to the wash durable material.